Sensor module

Abstract

The invention relates to a sensor module. The sensor module includes: a substrate including a first surface and a second surface in a front-back relationship, and a side surface including a first side surface; a first relay substrate having a first surface and a first back surface in a front-back relationship, the first relay substrate being attached to the first side surface in a posture in which the first back surface faces the first side surface; and a first inertial sensor including a first package mounted on the first surface of the first relay substrate and a first sensor element housed in the first package.

Description

Technical Field

[0001] The invention relates to a sensor module. Background Art

[0002] The inertial measurement device described in Patent Document 1 includes an inner shell, a sensor substrate mounted on the lower surface of the inner shell, and an outer shell covering the inner shell and accommodating the sensor substrate between the inner shell and the outer shell. In addition, the sensor substrate includes a substrate, a Z-axis angular velocity sensor and an acceleration sensor mounted on the upper surface of the substrate, and an X-axis angular velocity sensor and a Y-axis angular velocity sensor mounted on the side of the substrate.

[0003] In addition, a recess is formed on the lower surface of the inner shell, and the X-axis, Y-axis, and Z-axis angular velocity sensors and the acceleration sensor are arranged at positions overlapping the recess. In addition, a filling member is filled in the recess, and the entire area of ​​the Z-axis angular velocity sensor and the acceleration sensor is sealed by the filling member, and the upper half of the X-axis angular velocity sensor and the Y-axis angular velocity sensor is sealed.

[0004] In the inertial measurement device of Patent Document 1, a filling member is arranged to reduce the influence of noise vibration from the outside and improve the stability of detection accuracy.

[0005] Patent Document 1: Japanese Patent Application Publication No. 2017-020829

[0006] However, in the inertial measurement device of Patent Document 1, the X-axis angular velocity sensor and the Y-axis angular velocity sensor are mounted on the side surface of the substrate. Therefore, the mounting reliability of the X-axis angular velocity sensor and the Y-axis angular velocity sensor is low, and the detection characteristics may change over time. Summary of the invention

[0007] The sensor module of the present invention has:

[0008] A substrate having a first surface and a second surface in a front-back relationship and a side surface including a first side surface;

[0009] A first relay substrate having a first surface and a first back surface in a front-back relationship, and mounted on the first side surface with the first back surface facing the first side surface; and

[0010] a first inertial sensor including a first package mounted on the first surface of the first relay substrate and a first sensor element accommodated in the first package,

[0011] When the thickness direction of the substrate is set as a first direction,

[0012] The linear expansion coefficient of the substrate in the first direction is set to α1,

[0013] The linear expansion coefficient of the first relay substrate in the first direction is set to α2,

[0014] When the linear expansion coefficient of the first package in the first direction is set to α3,

[0015] The relationship of α1>α2>α3 is satisfied. BRIEF DESCRIPTION OF THE DRAWINGS

[0016] Figure 1 It is a top view showing the sensor module according to the first embodiment.

[0017] Figure 2 This is a three-dimensional exploded view of the sensor module.

[0018] Figure 3 Figure 1 AA line section view in.

[0019] Figure 4 Figure 1 BB line section view in.

[0020] Figure 5 is a cross-sectional view of the first interconnect substrate.

[0021] Figure 6 is a cross-sectional view of the second interconnect substrate.

[0022] Figure 7 is a cross-sectional view of the angular velocity sensor.

[0023] Figure 8 is a top view of the angular velocity sensor.

[0024] Fig. 9 Schematic diagram showing the driving state of the angular velocity sensor.

[0025] Fig.10 Schematic diagram showing the driving state of the angular velocity sensor.

[0026] Fig.11 It is a cross-sectional view of a first interconnect substrate according to the second embodiment.

[0027] Fig.12 It is a cross-sectional view of a second interconnect substrate according to the second embodiment.

[0028] Fig.13 It is a top view showing a sensor module according to a third embodiment.

[0029] Fig.14 yes Fig.13 CC line section view in.

[0030] Fig.15 yes Fig.13DD line section view in.

[0031] Fig.16 It is a cross-sectional view of a first interconnect substrate according to a fourth embodiment.

[0032] Fig.17 It is a cross-sectional view of a second interconnect substrate according to a fourth embodiment.

[0033] Description of Reference Numerals

[0034] 1…sensor module, 2…housing, 3…inner housing, 3a…upper surface, 31…threaded hole, 32…recess, 33…mounting table, 34…through hole, 4…housing, 41…threaded hole, 42…threaded hole, 43…recess, 5…substrate, 5a…upper surface, 5b…lower surface, 5c…first side surface, 5d…second side surface, 5e…third side surface, 5f…fourth side surface, 50…sensor substrate, 51…connector, 61…first relay substrate, 61a…surface, 61b…back surface, 62…second relay substrate, 62a…surface, 62b…back surface, 63…third relay substrate, 63a…surface, 63b…back surface, 64…fourth relay substrate, 64a…surface, 64b…back surface, 7X…X-axis angular velocity sensor, 7Y…Y-axis angular velocity sensor, 7Z…Z-axis angular velocity sensor device, 71…package, 72…base, 72a…surface, 72b…back, 721…recess, 73…cover, 74…sensor element, 740…base, 741…detection vibration arm, 742…driving vibration arm, 75…support substrate, 8…circuit element, B1…mounting screw, B2…mounting screw, EL…wiring, EL1…wiring, EL2…wiring, H1…solder, H11…upper solder, H12…lower solder, H2…solder, H21…upper solder, H22…lower solder, H3…solder, H31…upper solder, H32…lower solder, H4…solder, H41…upper solder, H42…lower solder, J…detection axis, P1…first row of pins, P2…second row of pins, ω…angular velocity, ωx…angular velocity, ωy…angular velocity, ωz…angular velocity. DETAILED DESCRIPTION

[0035] Hereinafter, the sensor module of the present invention will be described in detail according to the embodiments shown in the accompanying drawings. Figures 1 to 6 , Figures 11 to 17 In the figure, three axes orthogonal to each other are shown as X-axis, Y-axis and Z-axis. In addition, for the convenience of explanation, the direction parallel to the X-axis is also referred to as "X-axis direction", the direction parallel to the Y-axis is also referred to as "Y-axis direction", and the direction parallel to the Z-axis is also referred to as "Z-axis direction". In addition, the arrow side of the Z-axis direction is also referred to as "upper", and the opposite side is referred to as "lower".

[0036] First embodiment

[0037] Figure 1 It is a top view showing the sensor module according to the first embodiment. Figure 2 This is a three-dimensional exploded view of the sensor module. Figure 3 yes Figure 1 AA line section view in. Figure 4 yes Figure 1 BB line section view in. Figure 5 is a cross-sectional view of the first interconnect substrate. Figure 6 is a cross-sectional view of the second interconnect substrate. Figure 7 is a cross-sectional view of the angular velocity sensor. Figure 8 is a top view of the angular velocity sensor. Fig. 9 and Fig.10 Each of them is a schematic diagram showing the driving state of the angular velocity sensor.

[0038] Figure 1 The sensor module 1 shown is an inertial measurement sensor unit (IMU) that detects the posture or behavior of an object to be installed, such as a car or a robot. The object to be installed is not limited to a moving object such as a car or a robot, and may be a building such as a bridge, an elevated road, or a track. When the sensor module 1 is installed in a building, the sensor module 1 is used as a structural health monitoring system to check the stability of the building.

[0039] like Figure 1 and Figure 2 As shown, the sensor module 1 includes a housing 2 and a sensor substrate 50 accommodated in the housing 2 .

[0040] Shell 2

[0041] like Figure 1 and Figure 2 As shown, the housing 2 includes an inner housing 3 and an outer housing 4 that covers the inner housing 3. The inner housing 3 and the outer housing 4 are each made of aluminum. Thus, the housing 2 has sufficiently high rigidity. In particular, in this embodiment, the surfaces of the inner housing 3 and the outer housing 4 are each treated with an aluminum oxide film, thereby imparting insulation to the housing 2. However, the constituent materials of the inner housing 3 and the outer housing 4 are not particularly limited, and may be made of metal materials such as titanium, magnesium, and stainless steel, or ceramics such as aluminum oxide and titanium dioxide.

[0042] The inner shell 3 is a box-shaped body with an upper opening and a rectangular parallelepiped shape with two corners on one diagonal line chamfered to form a plane. In addition, screw holes 31 for fixing the outer shell 4 are formed at two corners on the other diagonal line of the inner shell 3, respectively.

[0043] In addition, the inner housing 3 has a recessed portion 32 opened in the upper surface 3a. In addition, the inner housing 3 has a mounting table 33 protruding from the bottom surface of the recessed portion 32 and mounting the sensor substrate 50. In addition, the inner housing 3 has a through hole 34 penetrating the lower surface and the upper surface of the mounting table 33. The through hole 34 is a hole for exposing a connector 51 described later to the outside of the housing 2.

[0044] The outer shell 4 is in the shape of a box with an opening at the bottom and a rectangular parallelepiped. The outer shell 4 covers the inner shell 3 from the top by inserting the inner shell 3 into the recess 43 opened at the bottom surface. In addition, the opening shape of the outer shell 4 is consistent with the outer shape of the inner shell 3. Thus, the outer shell 4 can be prevented from shaking relative to the inner shell 3.

[0045] In addition, threaded holes 41 overlapping with the threaded holes 31 are formed at two corners of the outer shell 4 located on one diagonal line. And the inner shell 3 and the outer shell 4 are fixed by the mounting screws B1 inserted through the threaded holes 31 and 41. However, the method of fixing the outer shell 4 to the inner shell 3 is not particularly limited. In addition, threaded holes 42 are formed at two corners of the outer shell 4 located on another diagonal line. And the sensor module 1 is mounted on the mounted body by the mounting screws B2 inserted through the two threaded holes 42. However, the mounting method to the mounted body is not particularly limited.

[0046] Sensor substrate 50

[0047] like Figure 1 , Figure 3 as well as Figure 4 As shown, the sensor substrate 50 has a substrate 5. The substrate 5 has an upper surface 5a as a first surface and a lower surface 5b as a second surface, which are in a front-back relationship with each other, and a side surface. Such a substrate 5 is placed on the mounting table 33 of the inner shell 3 with the lower surface 5b facing the lower side, and is screwed by screws not shown. However, the method of fixing the substrate 5 to the inner shell 3 is not particularly limited. In addition, the side surface of the substrate 5 has a first side surface 5c facing the negative side of the X-axis direction, a third side surface 5e facing the positive side of the X-axis direction opposite to the first side surface 5c, a second side surface 5d facing the positive side of the Y-axis direction, and a fourth side surface 5f facing the negative side of the Y-axis direction opposite to the second side surface 5d. Such a substrate 5 is a circuit substrate formed with a wiring EL, for example, composed of a multi-layer glass epoxy substrate. However, the structure of the base 5 is not particularly limited.

[0048] The sensor substrate 50 has a connector 51 mounted on the lower surface 5b of the substrate 5. The sensor substrate 50 and an external device are electrically connected via the connector 51.

[0049] In addition, if Figure 5As shown, the sensor substrate 50 has a first relay substrate 61 mounted on the first side surface 5c of the substrate 5. In addition, the first relay substrate 61 has a surface 61a as a first surface and a back surface 61b as a first back surface in a front-back relationship with each other. Moreover, the first relay substrate 61 is bonded to the first side surface 5c of the substrate 5 on the back surface 61b in a posture in which the normal lines of the surface 61a and the back surface 61b are along the X-axis, that is, in a posture orthogonal to the substrate 5. Such a first relay substrate 61 is a circuit substrate formed with wiring EL1, for example, composed of a multi-layer glass epoxy substrate. In addition, in the present embodiment, the wiring EL1 formed on the surface 61a and the wiring EL1 formed on the back surface are electrically connected via a through electrode formed by penetrating the first relay substrate 61.

[0050] In addition, when the first side surface 5c is viewed from above, the first relay substrate 61 is configured to protrude from the upper side and the lower side of the first side surface 5c. By forming such a structure, the first relay substrate 61 can be bonded to the substrate 5 from both sides of the upper surface 5a side and the lower surface 5b side. Therefore, the bonding strength between the first relay substrate 61 and the substrate 5 can be improved.

[0051] Such a first relay substrate 61 is mechanically bonded and electrically connected to the substrate 5 by the solder H1 as the first conductive part. This facilitates the electrical connection between the first relay substrate 61 and the substrate 5. However, the first conductive part is not particularly limited, and may be, for example, a conductive adhesive material, a metal bump, etc.

[0052] The solder H1 includes a plurality of rounded upper solders H11 and a plurality of rounded lower solders H12, wherein the upper solder H11 is formed over the upper surface 5a of the substrate 5 and the back surface 61b of the first relay substrate 61, and the lower solder H12 is formed over the lower surface 5b of the substrate 5 and the back surface 61b of the first relay substrate 61. In this way, by joining the first relay substrate 61 to the substrate 5 from both sides of the upper surface 5a and the lower surface 5b, the joining strength between the first relay substrate 61 and the substrate 5 can be improved. However, the method of joining the first relay substrate 61 to the substrate 5 is not particularly limited, and for example, either the upper solder H11 or the lower solder H12 can be omitted.

[0053] The sensor substrate 50 also includes an X-axis angular velocity sensor 7X as a first inertial sensor mounted on a surface 61a of the first relay substrate 61. The X-axis angular velocity sensor 7X is a sensor for detecting an angular velocity ωx around the X-axis.

[0054] In addition, if Figure 6As shown, the sensor substrate 50 has a second relay substrate 62 mounted on the second side surface 5d of the substrate 5. The second relay substrate 62 is a circuit substrate formed with the wiring EL2, for example, composed of a multilayer glass epoxy substrate. However, the configuration of the second relay substrate 62 is not particularly limited. In addition, the second relay substrate 62 has a surface 62a as a second surface and a back surface 62b as a second back surface in a front-back relationship with each other. Moreover, the second relay substrate 62 is bonded to the second side surface 5d of the substrate 5 on the back surface 62b in a posture in which the normal lines of the surface 62a and the back surface 62b are along the Y axis, that is, in a posture orthogonal to the substrate 5 and the first relay substrate 61.

[0055] In addition, when the second side surface 5d is viewed from above, the second relay substrate 62 is configured to protrude from the upper side and the lower side of the second side surface 5d. By forming such a configuration, the second relay substrate 62 can be bonded to the substrate 5 from both sides of the upper surface 5a and the lower surface 5b. Therefore, the bonding strength between the second relay substrate 62 and the substrate 5 can be improved.

[0056] Such a second relay substrate 62 is mechanically bonded and electrically connected to the substrate 5 by the solder H2 as the second conductive portion. Thus, the electrical connection between the second relay substrate 62 and the substrate 5 becomes easy. However, the second conductive portion is not particularly limited, and may be, for example, a conductive adhesive material, a metal bump, etc.

[0057] The solder H2 includes a plurality of rounded upper solders H21 and a plurality of rounded lower solders H22, wherein the upper solder H21 is formed over the upper surface 5a of the substrate 5 and the back surface 62b of the first relay substrate 62, and the lower solder H22 is formed over the lower surface 5b of the substrate 5 and the back surface 62b of the first relay substrate 62. In this way, by joining the second relay substrate 62 to the substrate 5 from both sides of the upper surface 5a side and the lower surface 5b side, the joining strength between the second relay substrate 62 and the substrate 5 can be improved. However, the method of joining the second relay substrate 62 to the substrate 5 is not particularly limited, and for example, either the upper solder H21 or the lower solder H22 can be omitted.

[0058] In addition, the sensor substrate 50 includes a Y-axis angular velocity sensor 7Y as a second inertial sensor mounted on the surface 62a of the second relay substrate 62. The Y-axis angular velocity sensor 7Y is a sensor for detecting an angular velocity ωy around the Y-axis.

[0059] In addition, if Figure 3As shown, the sensor substrate 50 has a Z-axis angular velocity sensor 7Z as a third inertial sensor mounted on the lower surface 5b of the substrate 5. The Z-axis angular velocity sensor 7Z is a sensor for detecting an angular velocity ωz around the Z axis. Thus, by having three inertial sensors, namely, the X-axis angular velocity sensor 7X, the Y-axis angular velocity sensor 7Y, and the Z-axis angular velocity sensor 7Z, the sensor module 1 can measure more inertia, and its convenience is improved.

[0060] The X-axis angular velocity sensor 7X, the Y-axis angular velocity sensor 7Y, and the Z-axis angular velocity sensor 7Z are respectively packaged surface-mounted components. Thus, they can exert high mechanical strength compared to mounted components with exposed elements. Furthermore, the X-axis angular velocity sensor 7X, the Y-axis angular velocity sensor 7Y, and the Z-axis angular velocity sensor 7Z can be easily mounted on the substrate 5.

[0061] In addition, except that the vibration frequencies of the sensor element 74 described later are different in order to suppress mutual interference, the basic structures of the X-axis angular velocity sensor 7X, the Y-axis angular velocity sensor 7Y and the Z-axis angular velocity sensor 7Z are the same, and are arranged in a manner that makes the postures orthogonal to each other with the detection axes facing the X-axis, Y-axis and Z-axis.

[0062] like Figure 7 and Figure 8 As shown, the X-axis angular velocity sensor 7X, the Y-axis angular velocity sensor 7Y, and the Z-axis angular velocity sensor 7Z each have a package 71 and a sensor element 74 housed in the package 71. In addition, the package 71 has a box-shaped base 72 and a cover 73. The base 72 has a recessed portion 721 opened on the surface 72a and supports the sensor element 74 housed in the recessed portion 721. The cover 73 is joined to the base 72 in a manner that closes the opening of the recessed portion 721. In addition, a connection terminal (not shown) electrically connected to the sensor element 74 is formed on the back surface 72b of the base 72.

[0063] In this embodiment, package 71 of X-axis angular velocity sensor 7X is a first package, and sensor element 74 of X-axis angular velocity sensor 7X is a first sensor element. In addition, package 71 of Y-axis angular velocity sensor 7Y is a second package, and sensor element 74 of Y-axis angular velocity sensor 7Y is a second sensor element.

[0064] The X-axis angular velocity sensor 7X is bonded to the surface 61a of the first relay substrate 61 at the back surface 72b of the base 72, and is electrically connected to the first relay substrate 61 via the connection terminals. In addition, the Y-axis angular velocity sensor 7Y is bonded to the surface 62a of the second relay substrate 62 at the back surface 72b of the base 72, and is electrically connected to the second relay substrate 62 via the connection terminals. In addition, the Z-axis angular velocity sensor 7Z is bonded to the lower surface 5b of the substrate 5 at the back surface 72b of the base 72, and is electrically connected to the substrate 5 via the connection terminals.

[0065] The sensor element 74 is, for example, a crystal vibration element having a driving vibration arm and a detecting vibration arm. Figure 8 In the structure of the crystal oscillator, there are a base 740 fixed to the base 72 via a support substrate 75, four driving vibration arms 742, and two detection vibration arms 741. In such a crystal oscillator element, when Fig. 9 As shown in FIG. 1 , when an angular velocity ω around the detection axis J is applied while a driving signal is applied to drive the vibration arm 742 to vibrate, as shown in FIG. Fig.10 As shown, the Coriolis force excites the detection vibration in the detection vibration arm 741. Then, the charge generated in the detection vibration in the detection vibration arm 741 by the detection vibration can be taken out as a detection signal, and the angular velocity ω can be obtained from the taken out detection signal.

[0066] The above is a comprehensive description of the configuration of the X-axis angular velocity sensor 7X, the Y-axis angular velocity sensor 7Y, and the Z-axis angular velocity sensor 7Z. The X-axis angular velocity sensor 7X is configured so that the detection axis J is along the X-axis, the Y-axis angular velocity sensor 7Y is configured so that the detection axis J is along the Y-axis, and the Z-axis angular velocity sensor 7Z is configured so that the detection axis J is along the Z-axis. However, the configuration of the X-axis angular velocity sensor 7X, the Y-axis angular velocity sensor 7Y, and the Z-axis angular velocity sensor 7Z is not particularly limited. For example, a configuration using a silicon MEMS vibration element as a sensor element may also be used.

[0067] In addition, if Figure 1 As shown, the sensor substrate 50 has a circuit element 8 as an electronic component mounted on the upper surface 5a of the substrate 5. The circuit element 8 is electrically connected to the X-axis angular velocity sensor 7X, the Y-axis angular velocity sensor 7Y, the Z-axis angular velocity sensor 7Z and the connector 51 via the substrate 5. The circuit element 8 is, for example, an MCU (Micro Controller Unit), which uniformly controls each part of the sensor module 1. Specifically, the circuit element 8 has a control circuit and an interface circuit, the control circuit controls the driving of the X-axis angular velocity sensor 7X, the Y-axis angular velocity sensor 7Y, and the Z-axis angular velocity sensor 7Z, and the interface circuit communicates with the outside.

[0068] The control circuit independently controls the driving of the X-axis angular velocity sensor 7X, the Y-axis angular velocity sensor 7Y, and the Z-axis angular velocity sensor 7Z, and independently detects the angular velocity around each axis of the X-axis, the Y-axis, and the Z-axis according to the detection signals output from the X-axis angular velocity sensor 7X, the Y-axis angular velocity sensor 7Y, and the Z-axis angular velocity sensor 7Z. The interface circuit receives and sends signals, accepts instructions from an external device via a connector 51, or outputs the detected angular velocity to an external device. There is no particular limitation on the communication method of the interface circuit, and in this embodiment, it is SPI (Serial Peripheral Interface) communication. SPI communication is a communication method suitable for connecting multiple sensors. Since all signals related to the angular velocity can be output from one pin, pin saving of the sensor module 1 can be achieved.

[0069] In addition, in addition to the above-mentioned X-axis angular velocity sensor 7X, Y-axis angular velocity sensor 7Y, Z-axis angular velocity sensor 7Z and circuit element 8, a plurality of electronic components are mounted on the substrate 5, but for the sake of convenience, their illustration and description are omitted.

[0070] Here, when the linear expansion coefficient in the thickness direction of the substrate 5, i.e., the Z-axis direction as the first direction, is set to α1, the linear expansion coefficient in the plane direction of the first relay substrate 61, i.e., the Z-axis direction along the thickness direction of the substrate 5, is set to α2, and the linear expansion coefficient in the plane direction of the package 71 of the X-axis angular velocity sensor 7X, specifically, the base 72, i.e., the Z-axis direction along the thickness direction of the substrate 5, is set to α3, the relationship of α1>α2>α3 is satisfied in the sensor module 1. In addition, in the present embodiment, α1 is about 40 ppm / °C, α2 is 12 ppm / °C, and α3 is about 7 ppm / °C. However, as long as the relationship of α1>α2>α3 is satisfied, the values ​​of these α1, α2, and α3 are not particularly limited.

[0071] By satisfying the relationship of α1>α2>α3, the mounting reliability of the X-axis angular velocity sensor 7X is improved. Specifically, when the X-axis angular velocity sensor 7X is directly mounted on the first side surface 5c of the substrate 5 as in the past, since the difference between the linear expansion coefficients α1 and α3 is large, it is possible that a large thermal stress is generated at the joint portion thereof, causing the solder H1 to peel off or cracks to form in the solder H1. In contrast, by interposing the first relay substrate 61 having a linear expansion coefficient α2 between the linear expansion coefficients α1 and α3 between the substrate 5 and the X-axis angular velocity sensor 7X as in the present embodiment, the thermal stress can be dispersed to the joint portion between the substrate 5 and the first relay substrate 61 and the joint portion between the first relay substrate 61 and the X-axis angular velocity sensor 7X. Therefore, the thermal stress applied to one joint portion is reduced, and the peeling or cracking of the solder H1 can be effectively suppressed, thereby improving the mounting reliability.

[0072] Although not shown in the figure, various circuit elements for the X-axis angular velocity sensor 7X, such as a capacitor, a regulator, and a power supply circuit, may be mounted on the first relay substrate 61. Thus, the circuit elements for the X-axis angular velocity sensor 7X can be easily mounted near the X-axis angular velocity sensor 7X, and the circuit characteristics are improved.

[0073] As with the first relay substrate 61 described above, when the linear expansion coefficient of the second relay substrate 62 in the plane direction, i.e., the Z-axis direction along the thickness direction of the substrate 5, is set to α4, and the linear expansion coefficient of the package 71 of the Y-axis angular velocity sensor 7Y, specifically, the base 72 in the plane direction, i.e., the Z-axis direction along the thickness direction of the substrate 5, is set to α5, in the sensor module 1, the relationship of α1>α4>α5 is satisfied. In addition, in the present embodiment, α4=α2, α5=α3. However, the values ​​of α4 and α5 are not particularly limited.

[0074] By satisfying the relationship of α1>α4>α5, the mounting reliability of the Y-axis angular velocity sensor 7Y is improved. Specifically, when the Y-axis angular velocity sensor 7Y is directly mounted on the second side surface 5d of the substrate 5 as in the past, since the difference between the linear expansion coefficients α1 and α5 is large, it is possible that a large thermal stress is generated at the joint portion thereof, causing the solder H2 to peel off or cracks to form in the solder H2. In contrast, by interposing the second relay substrate 62 having a linear expansion coefficient α4 between the linear expansion coefficients α1 and α5 between the substrate 5 and the Y-axis angular velocity sensor 7Y as in the present embodiment, the thermal stress can be dispersed to the joint portion between the substrate 5 and the second relay substrate 62 and the joint portion between the second relay substrate 62 and the Y-axis angular velocity sensor 7Y. Therefore, the thermal stress applied to one joint portion is reduced, and the peeling or cracking of the solder H2 can be effectively suppressed, thereby improving the mounting reliability.

[0075] Although not shown in the figure, various circuit elements for the Y-axis angular velocity sensor 7Y, such as a capacitor, a regulator, and a power supply circuit, may be mounted on the second relay substrate 62. Thus, the circuit elements for the Y-axis angular velocity sensor 7Y can be easily mounted near the Y-axis angular velocity sensor 7Y, and the circuit characteristics are improved.

[0076] The sensor module 1 of the present embodiment has been described above. As described above, such a sensor module 1 includes: a substrate 5 having an upper surface 5a as a first surface and a lower surface 5b as a second surface in a front-back relationship and a side surface including a first side surface 5c; a first relay substrate 61 having a surface 61a as a first surface and a back surface 61b as a first back surface in a front-back relationship, and mounted on the first side surface 5c in a posture that the back surface 61b faces the first side surface 5c; and an X-axis angular velocity sensor 7X as a first inertial sensor, including a package 71 as a first package mounted on the surface 61a of the first relay substrate 61 and a sensor element 74 as a first sensor element accommodated in the package 71. Furthermore, when the thickness direction of the substrate 5 is set as the first direction, i.e., the Z-axis direction, the linear expansion coefficient of the substrate 5 in the Z-axis direction is set as α1, the linear expansion coefficient of the first relay substrate 61 in the Z-axis direction is set as α2, and the linear expansion coefficient of the package 71 of the X-axis angular velocity sensor 7X in the Z-axis direction is set as α3, the relationship of α1>α2>α3 is satisfied. In this way, by interposing the first relay substrate 61 having a linear expansion coefficient α2 between the linear expansion coefficients α1 and α3 between the substrate 5 and the X-axis angular velocity sensor 7X, the thermal stress generated by the difference in linear expansion coefficients can be dispersed to the bonding portion between the substrate 5 and the first relay substrate 61 and the bonding portion between the first relay substrate 61 and the X-axis angular velocity sensor 7X. Therefore, stress is less likely to be concentrated, and mounting reliability is improved.

[0077] In addition, as described above, the side surface of the substrate 5 further includes a second side surface 5d different from the first side surface 5c. In addition, the sensor module 1 includes a second relay substrate 62 having a surface 62a as a second surface and a back surface 62b as a second back surface in a front-to-back relationship, and mounted on the second side surface 5d in a posture that the back surface 62b faces the second side surface 5d, and a Y-axis angular velocity sensor 7Y as a second inertial sensor, and includes a package 71 as a second package mounted on the surface 62a of the second relay substrate 62 and a sensor element 74 as a second sensor element accommodated in the package 71. Furthermore, when the linear expansion coefficient of the second relay substrate 62 in the Z-axis direction is set to α4, and the linear expansion coefficient of the package 71 of the Y-axis angular velocity sensor 7Y in the Z-axis direction is set to α5, the relationship of α1>α4>α5 is satisfied. Thus, by interposing the second relay substrate 62 having a linear expansion coefficient α4 between the linear expansion coefficients α1 and α5 between the substrate 5 and the Y-axis angular velocity sensor 7Y, the thermal stress generated by the difference in linear expansion coefficient can be dispersed to the bonding portion between the substrate 5 and the second relay substrate 62 and the bonding portion between the second relay substrate 62 and the Y-axis angular velocity sensor 7Y. Therefore, stress is less likely to be concentrated, and mounting reliability is improved.

[0078] Furthermore, as described above, the sensor module 1 includes the Z-axis angular velocity sensor 7Z as the third inertial sensor mounted on the upper surface 5a or the lower surface 5b of the substrate 5. This provides the sensor module 1 capable of measuring more inertia.

[0079] In addition, as described above, when the first side surface 5c is viewed from above, the first relay substrate 61 protrudes from the first side surface 5c toward the upper surface 5a side and the lower surface 5b side, and when the second side surface 5d is viewed from above, the second relay substrate 62 protrudes from the second side surface 5d toward the upper surface 5a side and the lower surface 5b side. Thus, the first relay substrate 61 can be bonded to the substrate 5 from both sides of the upper surface 5a side and the lower surface 5b side. Therefore, the bonding strength between the first relay substrate 61 and the substrate 5 can be improved. Similarly, the second relay substrate 62 can be bonded to the substrate 5 from both sides of the upper surface 5a side and the lower surface 5b side. Therefore, the bonding strength between the second relay substrate 62 and the substrate 5 can be improved.

[0080] In addition, as described above, the first relay substrate 61 is electrically connected to the substrate 5 via the solder H1 as the first conductive portion, and the second relay substrate 62 is electrically connected to the substrate 5 via the solder H2 as the second conductive portion. This facilitates the electrical connection between the first relay substrate 61 and the substrate 5. Similarly, the electrical connection between the second relay substrate 62 and the substrate 5 is facilitated.

[0081] Second embodiment

[0082] Fig.11 It is a cross-sectional view of a first interconnect substrate according to the second embodiment. Fig.12 It is a cross-sectional view of a second interconnect substrate according to the second embodiment.

[0083] This embodiment is the same as the first embodiment except that the position of the X-axis angular velocity sensor 7X on the first relay substrate 61 and the position of the Y-axis angular velocity sensor 7Y on the second relay substrate 62 are different. In addition, in the following description, this embodiment is described with the focus on the differences from the first embodiment, and the description of the same matters is omitted. In addition, in each figure of this embodiment, the same figure mark is marked for the same structure as the above embodiment.

[0084] like Fig.11 As shown, in this embodiment, when the first side surface 5c is viewed from above, that is, viewed from the X-axis direction, the X-axis angular velocity sensor 7X is arranged separately from the first side surface 5c. Figure 5 In comparison, Fig.11 In the embodiment, the X-axis angular velocity sensor 7X is configured to be offset to the negative side in the Z-axis direction in a manner that does not overlap with the first side surface 5c. The first relay substrate 61 is mounted on the first side surface 5c, so that a greater thermal stress is applied to the position overlapping with the first side surface 5c. Therefore, by configuring the X-axis angular velocity sensor 7X so as not to overlap with the first side surface 5c as in the present embodiment, thermal stress is difficult to be transmitted to the X-axis angular velocity sensor 7X. Therefore, the reduction in the detection characteristics of the X-axis angular velocity sensor 7X can be more effectively suppressed. In addition, in the present embodiment, the X-axis angular velocity sensor 7X is configured to be offset downward relative to the first side surface 5c, but it is not limited to this, and for example, it can also be configured to be offset upward.

[0085] Likewise, if Fig.12 As shown in FIG. 1 , when the second side surface 5d is viewed from above, that is, viewed from the Y-axis direction, the Y-axis angular velocity sensor 7Y is separated from the second side surface 5d. Figure 6 In comparison, Fig.12 In the embodiment, the Y-axis angular velocity sensor 7Y is configured to be offset to the negative side in the Z-axis direction in a manner that does not overlap with the second side surface 5d. The second relay substrate 62 is mounted on the second side surface 5d, so that a greater thermal stress is applied to the position overlapping with the second side surface 5d. Therefore, by configuring the Y-axis angular velocity sensor 7Y so as not to overlap with the second side surface 5d as in the present embodiment, it is difficult for thermal stress to be transmitted to the Y-axis angular velocity sensor 7Y. Therefore, it is possible to more effectively suppress the reduction in the detection characteristics of the Y-axis angular velocity sensor 7Y. In addition, in the present embodiment, the Y-axis angular velocity sensor 7Y is configured to be offset downward relative to the second side surface 5d, but it is not limited to this. For example, it can also be configured to be offset upward.

[0086] In the sensor module 1 as described above, when the first side surface 5c is viewed from above, the X-axis angular velocity sensor 7X is separated from the first side surface 5c, and when the second side surface 5d is viewed from above, the Y-axis angular velocity sensor 7Y is separated from the second side surface 5d. As a result, thermal stress is difficult to be transmitted to the X-axis angular velocity sensor 7X and the Y-axis angular velocity sensor 7Y. Therefore, it is possible to more effectively suppress the reduction in the detection characteristics of the X-axis angular velocity sensor 7X and the Y-axis angular velocity sensor 7Y.

[0087] According to the second embodiment as described above, the same effects as those of the first embodiment can be achieved.

[0088] Third embodiment

[0089] Fig.13 It is a top view showing a sensor module according to a third embodiment. Fig.14 yes Fig.13 CC line section view in. Fig.15 yes Fig.13 DD line section view in.

[0090] This embodiment is the same as the first embodiment except that the structure of the sensor substrate 50 is different. In addition, in the following description, this embodiment is described with the difference from the first embodiment as the center, and the description of the same matters is omitted. In addition, in each figure of this embodiment, the same figure mark is marked for the same structure as the above embodiment.

[0091] like Figures 13 to 15 As shown, the sensor substrate 50 of the present embodiment has a third relay substrate 63 mounted on the third side surface 5e and a fourth relay substrate 64 mounted on the fourth side surface 5f. These third relay substrate 63 and fourth relay substrate 64 are circuit substrates, and have the same configuration as the first relay substrate 61 and the second relay substrate 62. In addition, the third relay substrate 63 and the fourth relay substrate 64 are mounted on the substrate 5 by the same method as the first relay substrate 61 and the second relay substrate 62. In this way, by mounting the third relay substrate 63 and the fourth relay substrate 64, for example, compared with the above-mentioned first embodiment, the space where the circuit elements can be mounted is increased, so the degree of freedom in design is increased. In addition, for example, by mounting all or part of the circuit elements mounted on the substrate 5 in the first embodiment on the third relay substrate 63 and the fourth relay substrate 64, the substrate 5 can also be miniaturized.

[0092] The third relay substrate 63 has a surface 63a as the third surface and a back surface 63b as the third back surface in a front-back relationship. Moreover, the third relay substrate 63 is bonded to the third side surface 5e of the substrate 5 on the back surface 63b in a posture in which the normal lines of the surface 63a and the back surface 63b are along the X-axis, that is, in a posture parallel to the first relay substrate 61. In addition, when the third side surface 5e is viewed from above, the third relay substrate 63 is configured to protrude to the upper side and the lower side of the third side surface 5e. Such a third relay substrate 63 is mechanically bonded to the substrate 5 by the solder H3 as the third conductive part, and is electrically connected. The solder H3 includes a plurality of rounded upper solders H31 and a plurality of rounded lower solders H32, the upper solders H31 are formed over the upper surface 5a of the substrate 5 and the back surface 63b of the third relay substrate 63, and the lower solders H32 are formed over the lower surface 5b of the substrate 5 and the back surface 63b of the third relay substrate 63.

[0093] In addition, the sensor substrate 50 has an X-axis angular velocity sensor 7X as a third inertial sensor mounted on the surface 63a of the third relay substrate 63. That is, the sensor substrate 50 of the present embodiment has a pair of X-axis angular velocity sensors 7X. According to such a configuration, by detecting the angular velocity ωx based on the detection signals output from each X-axis angular velocity sensor 7X, the noise is reduced compared to the first embodiment described above, and the angular velocity ωx can be detected with higher accuracy. The detection signal output from the X-axis angular velocity sensor 7X mounted on the surface 63a of the third relay substrate 63 can also be calculated together with the detection signal output from the X-axis angular velocity sensor 7X mounted on the surface 61a of the first relay substrate 61. The calculation process can be performed by the MCU (Micro Controller Unit) as the circuit element 8, and the calculation process can also be an average process.

[0094] The fourth relay substrate 64 has a surface 64a as a fourth surface and a back surface 64b as a fourth back surface in a front-back relationship. Moreover, the fourth relay substrate 64 is bonded to the fourth side surface 5f of the substrate 5 on the back surface 64b in a posture in which the normal lines of the surface 64a and the back surface 64b are along the Y axis, that is, in a posture parallel to the second relay substrate 62. In addition, when the fourth side surface 5f is viewed from above, the fourth relay substrate 64 is configured to protrude to the upper side and the lower side of the fourth side surface 5f. Such a fourth relay substrate 64 is mechanically bonded to the substrate 5 by the solder H4 as the fourth conductive portion, and is electrically connected. The solder H4 includes a plurality of rounded upper solders H41 and a plurality of rounded lower solders H42, the upper solders H41 are formed over the upper surface 5a of the substrate 5 and the back surface 64b of the fourth relay substrate 64, and the lower solders H42 are formed across the lower surface 5b of the substrate 5 and the back surface 64b of the fourth relay substrate 64.

[0095] In addition, the sensor substrate 50 has a Y-axis angular velocity sensor 7Y as a fourth inertial sensor mounted on the surface 64a of the fourth relay substrate 64. That is, the sensor substrate 50 of the present embodiment has a pair of Y-axis angular velocity sensors 7Y. According to such a configuration, by detecting the angular velocity ωy based on the detection signals output from each Y-axis angular velocity sensor 7Y, the noise is reduced compared to the first embodiment described above, and the angular velocity ωy can be detected with higher accuracy. The detection signal output from the Y-axis angular velocity sensor 7Y mounted on the surface 64a of the fourth relay substrate 64 can also be calculated together with the detection signal output from the Y-axis angular velocity sensor 7Y mounted on the surface 62a of the second relay substrate 62. The calculation process can be performed by the MCU (Micro Controller Unit) as the circuit element 8, and the calculation process can also be an average process.

[0096] In addition, the sensor substrate 50 has a pair of Z-axis angular velocity sensors 7Z mounted on the lower surface 5b of the substrate 5. According to such a configuration, by detecting the angular velocity ωz based on the detection signals output from each Z-axis angular velocity sensor 7Z, the noise is reduced compared to the first embodiment, and the angular velocity ωz can be detected with higher accuracy. The detection signals output from the pair of Z-axis angular velocity sensors 7Z mounted on the lower surface 5b of the substrate 5 can also be calculated. The calculation process can be performed by the MCU (Micro Controller Unit) as the circuit element 8, and the calculation process can also be an average process.

[0097] In the sensor module 1 described above, the side surface of the substrate 5 further includes a third side surface 5e opposite to the first side surface 5c and a fourth side surface 5f opposite to the second side surface 5d. In addition, the sensor module 1 includes: a third relay substrate 63 having a surface 63a as a third surface and a back surface 63b as a third back surface in a front-to-back relationship, and mounted on the third side surface 5e with the back surface 63b facing the third side surface 5e; an X-axis angular velocity sensor 7X as a third inertial sensor mounted on the surface 63a of the third relay substrate 63; a fourth relay substrate 64 having a surface 64a as a fourth surface and a back surface 64b as a fourth back surface in a front-to-back relationship, and mounted on the fourth side surface 5f with the back surface 64b facing the fourth side surface 5f; and a Y-axis angular velocity sensor 7Y as a fourth inertial sensor mounted on the surface 64a of the fourth relay substrate 64. According to such a configuration, for example, compared with the first embodiment described above, the space where circuit elements can be mounted is increased, so the degree of freedom in design is increased. In addition, for example, by mounting all or part of the circuit elements mounted on the substrate 5 in the first embodiment on the third relay substrate 63 and the fourth relay substrate 64, the substrate 5 can also be miniaturized. In addition, by detecting the angular velocity ωx based on the detection signal output from each X-axis angular velocity sensor 7X, the noise is reduced, and the angular velocity ωx can be detected with higher accuracy. Similarly, by detecting the angular velocity ωy based on the detection signal output from each Y-axis angular velocity sensor 7Y, the noise is reduced, and the angular velocity ωy can be detected with higher accuracy.

[0098] According to the third embodiment as described above, the same effects as those of the first embodiment can be achieved.

[0099] Fourth embodiment

[0100] Fig.16 It is a cross-sectional view of a first interconnect substrate according to a fourth embodiment. Fig.17 It is a cross-sectional view of a second interconnect substrate according to a fourth embodiment.

[0101] This embodiment is the same as the first embodiment except that the structure of the sensor substrate 50 is different. In addition, in the following description, this embodiment is described with the difference from the first embodiment as the center, and the description of the same matters is omitted. In addition, in each figure of this embodiment, the same figure mark is marked for the same structure as the above embodiment.

[0102] like Fig.16As shown, in the sensor substrate 50 of the present embodiment, the first relay substrate 61 and the substrate 5 are electrically connected by a plurality of first pins P1. Specifically, in the present embodiment, the wiring EL1 is not formed on the back surface 61b of the first relay substrate 61. In addition, the plurality of first pins P1 electrically connected to the wiring EL1 formed on the front surface 61a are arranged to penetrate the first relay substrate 61. And, by bonding the portion of the first pins P1 protruding from the back surface 61b to the solder H1, the first relay substrate 61 and the substrate 5 are electrically connected. According to such a configuration, the wiring EL1 can be omitted from the back surface 61b of the first relay substrate 61, so that the configuration of the first relay substrate 61 becomes simple.

[0103] Likewise, if Fig.17 As shown, in the sensor substrate 50 of the present embodiment, the second relay substrate 62 is electrically connected to the substrate 5 through a plurality of second pins P2. Specifically, in the present embodiment, the wiring EL2 is not formed on the back surface 62b of the second relay substrate 62. In addition, a plurality of second pins P2 electrically connected to the wiring EL2 formed on the front surface 62a are arranged to penetrate the second relay substrate 62. And, by bonding the portion of the second pins P2 protruding from the back surface 62b to the solder H2, the second relay substrate 62 is electrically connected to the substrate 5. According to such a configuration, the wiring EL2 can be omitted from the back surface 62b of the second relay substrate 62, so that the configuration of the second relay substrate 62 becomes simple.

[0104] The sensor module 1 as described above includes a first pin row P1 and a second pin row P2, wherein the first pin row P1 is arranged to pass through the first relay substrate 61 and is electrically connected to the solder H1, and the second pin row P2 is arranged to pass through the second relay substrate 62 and is electrically connected to the solder H2. According to such a configuration, the wiring EL1 can be omitted from the back surface 61b of the first relay substrate 61, so the configuration of the first relay substrate 61 becomes simple. Similarly, the wiring EL2 can be omitted from the back surface 62b of the second relay substrate 62, so the configuration of the second relay substrate 62 becomes simple.

[0105] According to the fourth embodiment as described above, the same effects as those of the first embodiment can be achieved.

[0106] The sensor module of the present invention has been described above based on the illustrated embodiments, but the present invention is not limited thereto, and the configuration of each part can be replaced by any configuration having the same function. In addition, any other configuration can be added to the present invention. In addition, the various embodiments can be appropriately combined.

Claims

1. A sensor module, characterized in that: have: A substrate having a first surface and a second surface in a front-back relationship and a side surface including a first side surface; A first relay substrate having a first surface and a first back surface in a front-back relationship, and mounted on the first side surface with the first back surface facing the first side surface; as well as a first inertial sensor including a first package mounted on the first surface of the first relay substrate and a first sensor element accommodated in the first package, When the thickness direction of the substrate is set as a first direction, The linear expansion coefficient of the substrate in the first direction is set to α1, The linear expansion coefficient of the first relay substrate in the first direction is set to α2, When the linear expansion coefficient of the first package in the first direction is set to α3, The relationship of α1>α2>α3 is satisfied.

2. The sensor module according to claim 1, characterized in that: The side surface of the substrate further includes a second side surface different from the first side surface, The sensor module has: A second relay substrate having a second surface and a second back surface in a front-back relationship, and mounted on the second side surface with the second back surface facing the second side surface; as well as a second inertial sensor including a second package mounted on the second surface of the second relay substrate and a second sensor element accommodated in the second package, When the linear expansion coefficient of the second relay substrate in the first direction is set to α4, When the linear expansion coefficient of the second package in the first direction is set to α5, The relationship of α1>α4>α5 is satisfied.

3. The sensor module according to claim 1, characterized in that: The sensor module includes a third inertial sensor mounted on the first surface or the second surface of the substrate.

4. The sensor module according to claim 2, characterized in that: When the first side surface is viewed from above, the first relay substrate protrudes from the first side surface toward the first surface side and the second surface side. The second interconnect substrate protrudes from the second side surface toward the first surface and the second surface when the second side surface is viewed from above.

5. The sensor module according to claim 2, characterized in that: When the first side surface is viewed from above, the first inertial sensor is arranged separately from the first side surface. The second inertial sensor is arranged to be separated from the second side surface when the second side surface is viewed from above.

6. The sensor module according to claim 2, characterized in that: The first relay substrate is electrically connected to the substrate via a first conductive portion. The second relay substrate is electrically connected to the substrate via a second conductive portion.

7. The sensor module according to claim 6, characterized in that: have: a first row of needles, arranged to pass through the first relay substrate, the first row of needles being electrically connected to the first conductive portion; and The second row of needles is disposed to penetrate the second relay substrate, and the second row of needles is electrically connected to the second conductive portion.

8. The sensor module according to claim 2, characterized in that: The side surface of the substrate further includes a third side surface opposite to the first side surface and a fourth side surface opposite to the second side surface. The sensor module has: A third relay substrate having a third surface and a third back surface in a front-back relationship, and mounted on the third side surface with the third back surface facing the third side surface; a third inertial sensor mounted on the third surface of the third relay substrate; a fourth relay substrate having a fourth front surface and a fourth back surface in a front-back relationship, and mounted on the fourth side surface with the fourth back surface facing the fourth side surface; and A fourth inertial sensor is mounted on the fourth surface of the fourth relay substrate.

9. A sensor module, characterized in that: have: A substrate having a first surface and a second surface in a front-back relationship and a side surface including a first side surface; A first relay substrate having a first surface and a first back surface in a front-back relationship, and mounted on the first side surface with the first back surface facing the first side surface; as well as The first inertial sensor includes a first package mounted on the first surface of the first relay substrate and a first sensor element accommodated in the first package.

Images